We continue to explore the clinical, laboratory, neuropsychiatric and imaging features of at-risk members of families with FamilialEncephalopathy with Neuroserpin Inclusion Bodies (FENIB). At the NIH Clinical Center we have seen 25 individuals at risk for this disorder for full clinical evaluations. The clinical facet of this project continues to be a long term exploration of the natural history of family members at risk. This will increase our insight into the pathophysiology and clinical presentation of FENIB. These families provide not only rich clinical insight but the opportunity to understand the controversy surrounding presymptomatic testing in late onset neurodegenerative disorders. Further clinical delineation, appropriate diagnostic and management strategies and assessment of counselling needs remain the clinical goals for this project. Dr. Lacbawan is currently developing a mouse model for FENIB which will further help to elucidate the phenotype and genotypic variation and possible therapeutic options under the direction of Dr. Muenke.